One reason I’ve been so lax about posting this last year or two is that we’ve been building a house, and it’s taken too much time and energy to drink much or write about it. Anyway, the house is done now, it’s up in the Catskill Mountains, and I have successfully put aside a corner of the basement for a wine cellar. Finally! I have the chance to get this right, so I’m looking for (literally?) concrete advice from those who’ve been through it.

The basement is below grade, the wine cellar will use the north and the eastern walls as thermal mass. These walls are 10” poured concrete with a thoroseal coat on the exterior. Currently, the basement ceiling has not been insulated; while I had hoped to do the whole basement ceilings in icynene, I have a lot of batt insulation left over, including some R37 (as well as R19) that I may just use for the wine cellar so that I can get on and finish it. The basement floor is poured concrete.

I don’t intend to use any electrical equipment in this cellar, other than possibly the de-humidifier. If I insulate correctly, there’s no reason I should have any wild temperature swings. We do have exterior temperature extremes up here over the course of the year, and I don’t yet have the experience to know how they may affect the ambient temperature in this corner of the basement. But the few months here so far show no great overnight swings, and that’s with an unfinished large open basement with exterior sliding glass doors.

My main question to anyone who’s been through similar circumstances, is whether I should do anything else to the two concrete walls: vapor barrier, studs, batt, foam board? Or will the 10” frost wall likely supply enough insulation on its own? I will gladly take advice on the right approach to the two interior walls we need to build; my intent is for wooden frames, sheetrock, vapor barrier, ample insulation (probably use up this fiberglass batt, even though I prefer icynene) and a simple finish. The room will be about 10’ x 8’ – nothing flash like you see at the back of the Wine Spectator, just a lovely passive wine cellar so that I don’t have to keep going to Chelsea every time I want one of my nice bottles.

Tony, my guess is your situation is similar to mine, though your average temps probably are 8-10° F below Westchester.

We have an old frame house, with below grade rock walls in cellar. I built a corner cellar with 2 X 6 framing, allows r-19 pink insulation. R-30 in ceiling, left below grade walls and concrete floor as heat sinks. Vapor barrier all around (even rock walls), "greenboard" drywall. Foam insulation and caulking on all the seams. I couldn't fit an insulated exterior door in space (low ceilings), so I put an interior door in, then drilled holes to put in expanding foam insulation, then put 2" extruded foam insulation panel on inside.

So far (4 years) I'm very happy with performance. Not sure the vapor barrier is needed on rock walls, but it doesn't seem to hurt. My temps are very stable day to day, generally the top of the cellar tops out at about 68° for a couple days on last heat wave of summer (when ground is warmest). Towards the floor it is several degrees cooler. Slowly cools to 50°F in winter. I keep long term bottles lower. I put in an old AC unit that if I'm home I crank for an hour on the hottest days, bring ceiling temp down to 64 or so, but I really feel a one week stretch in upper 60s won't do bottles any real harm.

Tony Fletcher wrote:I don’t intend to use any electrical equipment in this cellar, other than possibly the de-humidifier...

...just a lovely passive wine cellar...

You mean the humdifier? [You wouldn't want to de-humidify your cellar, for fear of what it would do to the corks - unless maybe you're 100% screw cap.]

I guess I don't understand what you're doing here: If there isn't any electrical equipment, i.e. if there isn't any artificial cooling, i.e. if it's a 100% passive cellar, then there aren't any special construction techniques needed - it's just another place where cases of stuff are stored.

Tony Fletcher wrote:I don’t intend to use any electrical equipment in this cellar, other than possibly the de-humidifier...

...just a lovely passive wine cellar...

You mean the humdifier? [You wouldn't want to de-humidify your cellar, for fear of what it would do to the corks - unless maybe you're 100% screw cap.]

I guess I don't understand what you're doing here: If there isn't any electrical equipment, i.e. if there isn't any artificial cooling, i.e. if it's a 100% passive cellar, then there aren't any special construction techniques needed - it's just another place where cases of stuff are stored.

FWIW, I need to dehumidify my passive cellar in the summer. Otherwise, humidity levels can climb to 85% + causing mold problems with the labels. Rather than using an electric dehumidifier which probably would throw off some heat, I use those DAMP RID crystals that are widely available. Inexpensive and they seem to keep humidity in the 70-75% range...good for corks, bad for mold.
'Winger

Thanks for all the advice so far... I had missed the previous thread because off being so busy moving into the house finally (I really want to get back to spending more time on here, believe me) but I also wanted a thread that kept away from detailed conversation on coolers and ACs etc. I just want to deal with making the most of the natural thermal mass and insulate the framed walls to the best of shared knowledge. I'd be surprised and upset if it doesn't work out.

Dale - I may give you a call at some point for finer details.

Nathan - the need for a de-humidifier is because I live in one of the most humid climates known to man - it can run 100% humidity for months on end here.

I too have to fight high humidity levels in summer in my passive cellar. We run a dehumdifier in the general basement, which does raise basement temps a bit. But I try to do a little "management" - opening cellar windows on the occasional cool dry night.

I think it's probably worthwhile to worry about humidity in say the Southwest US. But humidity levels in below grade situations in eastern US are not really a concern.

As to idea its just another place where things are stored, my cellar is generally a good 6-10° cooler than surrounding basement. With good insulation, and floor as a heat sink, it makes a difference.

One other thing to think about is lighting. I use one compact fluorescent bulb. It's on basic basement lighting, but has a separate stringpull on/off. I am very careful about turning off, though even if I forget it will go off when I turn off basement lights. I'd strongly suggest CFL for heat reasons. If you use incandescent, I'd try to find a timer that will turn off light after a while- a 75W incandescent will heat up a cellar.

Tony, I did exactly the same thing with a west/north wall cement block and the east/south wall frame/insulation, etc. I put in electric and a wine cooler for safety sake, which rarely runs.

We've got no insulation on the outer cement block walls, R37 on the walls and R60 in the ceiling.

Call if I can give you any help -- our cellar opens into a finished room which is heated to 62 -- my wine library and view ports into a koi pond make it a great place to spend time -- and some heat gets in through the door which is insulated but metal and therefore acts something like a radiator into the cellar.

I did almost all the work myself -- electric excluded -- so it can't be very hard or difficult.

Two thoughts -- use a low energy light bulb and hook it up to the door so that the light turns on and off as you open and close the door, respectively. They cost less than $10 at Home Depot, or at least did five years ago.

Also, put a mat with holes on the floor -- I'll give you a couple of links if you need them. The floor acts as a heat sink -- about 28 degrees F here in the winter and it can be cold standing on it taking inventory, etc. Also, it reduces the chance of breakage if you drop a bottle.

Finally, a mini/max thermometer and a humidity gauge are both excellent investments. It's surprising how much humidity in particular can flucuate.

Really not much to add at this point so just piling on. My situation was similar in that my exterior walls are north and west and my interior are east and south. No insulation on the exterior walls although I did frame and drywall them for a consistent look and make attaching racks easier. Insulate interior walls and ceiling. Left the floor concrete but painted it to resemble tile. Put in recessed lighting on dimmers and have one dedicated circuit into the room in case I need to add a chiller later. My doors are solid wood.

Like Bob my cellar opens up into finished space but since the entire house is on one HVAC unit it is somewhat warmer than 62 outside the cellar. Generally varies from 66-74 depending upon the season. However, inside the cellar stays an almost constant 61. I have had the min-max thermometer in there for about a year and the range is from 60-63.

I do have one north facing window in the cellar that lets in some light that I need to address eventually but since I don't see a temp swing and since the light does not shine directly on the wine I have been slow to address it.

Gold's book is probably worth the investment, Tony. One question from my memory of the book--how far below grade is the top of the cellar? I seem to recall some outside insulation work being done if you were too close to ground level.

Joe
Re: outside insulation, we do have thoroseal on the exterior; not sure if it's the very best insulation known to man but it's what our builder recommended. The corner that will be the cellar is underground but for maybe the top few inches of the eastern wall.

Brian
I'm interested: Does framing and sheet-rocking those interior concrete walls affect the thermal mass in any, shape or form? It's encouraging to see just how constant your cellar has remained.

Bob:
I will probably call you when we get the builder in to frame out these interior walls. If nothing else, it would be nice to chat. I've long kept max/mim thermometers and humidity readers. Useful tools. The idea about the automatic light is well taken, as is Dale's point about making sure it's not incandescent.

This is most likely more of the same, Tony, but I'm so happy for you that I had to let you know what I did. New house, unfinished basement. Two walls of north corner made of 12" cinder block. I left the block walls as is (except for a little paint) and insulated the ceiling (in addition to what was there) and insulated the two other walls. I used standard fiberglass as well as Styrofoam insulation for the two walls and ceiling. I then finished the two walls and ceiling in stained oak and put in an oak floor right on top if the poured concrete. It has been wonderful for over 10 years now. One thing I'd suggest: If you are going to do any staining or painting with a water-proofing paint (by UGL, for instance) do it before you put any wine in - that smell stays around for a while.
Most importantly, have fun!

I'm interested: Does framing and sheet-rocking those interior concrete walls affect the thermal mass in any, shape or form? It's encouraging to see just how constant your cellar has remained.

The framing and sheet rock does not noticable affect the thermal mass although I am sure it does in some small manner. Compared to the portion that is still unfinished one can feel no difference. As a contrast in the portion that I finished I first attached furring strips to the wall and sheet rock to leave a small air gap then framed and insulated and sheet rock again and that did a rather good job of cutting down on the heat sink properties of the concrete walls.

Brian Gilp wrote: As a contrast in the portion that I finished I first attached furring strips to the wall and sheet rock to leave a small air gap then framed and insulated and sheet rock again and that did a rather good job of cutting down on the heat sink properties of the concrete walls.

The heat sink properties of the concrete walls... Hadn't been thinking about that. Judging by some of the comments on this thread, other people didn't worry much about it either. Anyone think that it's a concern? I quite like the idea of the exposed concrete walls...

And while on that subject, I'm interested about the policy of covering the concrete floor, even with just a holed mat, per Bob Ross. Do I assume the "heat sink" properties of the concrete floor serves as a negative in warmer weather? Weather very rarely pushes to about 90 degrees in the Catskills, and based on what I've seen from our open basement, I doubt it will force an insulated corner much above 65F. On the other hand, in our long and cold winters, would a heat sink serve as an advantage?

Tony, I've thought the bare walls and floors (hence the holes in the floor mats) are positives. Our outer walls have never been warmer than 55F in the hottest part of the summer, except in one two by two foot area where the wall is above the foundation -- I put a R17 piece of foam insulation over that section.

Normally the walls fluctuate between 40 and 55F. The floor gets down to 30F in a cold winter but is usually around 40 in the hottest summer.

You may have somewhat cooler readings, depending on your micro-climate, but the Ramapos and the Catskills are generally about the same temps based on my hiking maps.

You can always insulate later if you find bare walls and floor a problem. I wouldn't bother at the getgo except for aesthetic reasons.

The heat sink properties of the concrete walls... Hadn't been thinking about that. Judging by some of the comments on this thread, other people didn't worry much about it either. Anyone think that it's a concern?

For your cellar, I should not be a concern. I was talking about the portion of my basement that I was turning into living space and for which I want to be able to maintain a higher temperature without pumping in excessive heating (again since I have one HVAC system for the entire house).

Considering the xhundredthousand dollars it cost to build the house, complete with the 10" frost wall and concrete floors, any sign of water damage after 3" of rain and I'll be going after the builder!

I've got the room framed with 2x6, insulated with greenboard and R38 batt insulation on the two interior walls and ceiling. There's icynene insulation already up in the (insert technical term for space between wall and ceiling!), and we just need to cover that, build a chase around a couple of pipes, get a solid core door in place of the simple one currently sufficing, paint out the greenboard and Bob's your uncle, I should have a fully functioning wine cellar.

One surprise already: after insulating this room, the temperature within it rapidly dropped a few more degrees, from 52F to 49F. I'm wondering how much colder it may get over the course of REAL winter (as opposed to the early winter snowfalls/icestorms/subzero temps we've already had this year in the Catskills). Bob, I know you said your floor and walls can get pretty cold - what kind of temperatures does your room hold at during the winter?

And keeping the cold concrete floor exposed encourages what heat there is to spread downwards to the floor, correct?

Tony Fletcher wrote:Thanks for all the advice so far... I had missed the previous thread because off being so busy moving into the house finally (I really want to get back to spending more time on here, believe me) but I also wanted a thread that kept away from detailed conversation on coolers and ACs etc. I just want to deal with making the most of the natural thermal mass and insulate the framed walls to the best of shared knowledge. I'd be surprised and upset if it doesn't work out. Tony

Tony,
I understand that you don't want to get into the electrical stuff in this thread, but I was thinking that if you go ahead and wire the electricity now and don't need it later, then it's not much lost. However, if you do not wire it now and do need it later, then it is likely to be more expensive, or time consuming after the cellar is built. Just a thought.